10027: Layer's data source is referenced via a UNC path
Accessing data using UNC (Universal/Uniform/Unified Naming Convention) paths uses network file access instead of direct disk access, which can affect drawing performance.
Solutions
Do one of the following:
Do nothing. Accept the performance as-is.
Review the drawing metrics for this layer. If you are sharing the layer, review the data access metrics for the service. Learn about performance in ArcGIS Pro.
Make a local copy of the data sources on your computer, and use absolute paths.
Additional information
A path specifies a unique location in a file system by describing the hierarchy of directory folders and files on a computer network. An absolute (full) path begins with a drive letter followed by a colon. For example:
D:\Data\Final\EastValley\powerlines
UNC paths use a syntax for specifying folders and files on a network of computers. The syntax is as follows:
\\<computer name>\<shared directory>\
It includes any number of directories and terminates with a directory or file name. For example:
\\pondermatic\public\studyarea.gdb
\\omnipotent\shared_stuff\wednesday\tools
In ArcGIS Pro, you can use an absolute or UNC path anywhere a path is requested. It is particularly advantageous for shared data over a network. Data can be stored on one computer and everyone with access to the computer can access the data via its path.
There may be a performance disadvantage when using UNC paths because network file access is typically slower than direct disk access on your local computer (using absolute paths), which can affect map drawing performance.
Absolute paths can also be specified using a relative path, which is a location relative to a current directory. Relative paths do not have an impact on map drawing performance.